Berrin was one of Lupinia and Muskar Muskar's children. S/he was a slibling of Pippat Muskar, Gretty Muskar, Wortle Muskar and Bappik Muskar. S/he and his/her siblings and parents were kept hostages by two vermin before Yoofus Lightpaw and Wild Doogy Plumm rescued them.